Whenever you use accounts that use 2 different brokers, they sometimes have different names for instruments like GOLD or Indices.
For example, 1 broker can use GOLD and another broker can use XAUUSD. Therefore you would have to map GOLD to XAUUSD so the trade copier can know what pair to copy to.
If there is no difference in the symbol name, check both accounts forex suffix on the account settings.
Forex pairs are mapped by the account suffix setting. Go to account settings, then forex suffix sub-menu and make sure it is set with the appropriate suffix. For example, if EURUSD is listed as EURUSD.pro, set .pro as the suffix. If it is listed as EURUSD, choose No suffix.